Head shrinking is rumored to have occurred all over the world, but documented only among a few indigenous South American tribes living in Peru and Ecuador. To the Jivaroan people, a head taken from an enemy and shrunk—called a tsantsa—was more than just a battle trophy. Jivaro warriors believed that the ritual of shrinking the head paralyzed the spirit of their foe and prevented it from taking revenge, and also passed the victim’s strength onto the killer.

How do you take a flesh-and-bone head and shrink it? A typical Jivaro head-shrinking ritual, as recorded by European explorers in the 19th century, went something like this.

Step One: Deflesh

After getting a safe distance away from the battlefield with the severed heads of fallen enemies, victorious warriors feast, and then begin the work of making the tsantsa. First, the victim's scalp is removed, starting at an incision made across the back of the neck parallel to the bottoms of the ears. The warrior tugs on a flap of skin created by this cut and pulls toward the top of the head and then again toward the face, peeling the skin away from the skull on the back and top of the head. He then uses a knife or a sharpened piece of wood to work the flesh away from the bone around the facial features and scrape away the cartilage from the nose and ears. The eyelids are sewn shut and the lips held together with three wooden pins. Eyewitness accounts report that an experienced warrior could de-flesh a head this way in as little as 15 minutes.

Now, the stumbling block for me, whenever I thought about shrunken heads before researching them (not that it was something I thought about often, I swear I’m not a weirdo), was how the skull was miniaturized. Turns out, it wasn’t. Once the skin was removed, Jivaro warriors simply tossed the skulls away.

Step Two: Simmer

With the flesh taken from the head, the warrior goes to the nearest river with a ceremonial pot to gather water. The filled pot is set on a fire to heat up, and the flesh from the head is placed in it to simmer for an hour or two. When it’s removed, the head is a little smaller than it was originally, but not much. The head is turned inside out and stripped of any remaining fat, cartilage or muscle, and the incision on the back of the neck is sewn shut.

Step Three: Apply Stones and Sand

The head, now completely sealed except for the hole where the neck used to attach, is further shrunk with sand and stones heated on another fire. The hot stones are dropped into the head through the neck hole and the head is rotated continuously to avoid scorching. When the head shrinks and becomes too small to accommodate the stones, sand is poured in it instead and the head is shaken to drive the sand into the crevices the stones couldn’t reach. Once the head is the right size, the warrior carefully uses hot stones to sear the exterior skin and shape the head and facial features. The finished product is then left to further dry and harden. The entire process takes about a week.

After the head is done, the warriors and the rest of the tribe partake in more victory feasts, the last of which may happen up to a year after the battle it celebrates. Once these rituals are complete, the shrunken head has served its purpose for the warrior. Its significance was in the process of its creation, and not the final product. The tsantsa is usually then discarded in a river or in the jungle, or given to a child in the warrior’s family or village as a toy.